A method for five- and six-membered heterocycle formation by palladium-catalyzed C-H/N-H coupling is presented. The method employs a picolinamide directing group, PhI(OAc)(2) oxidant, and toluene solvent at 80-120 degrees C. Cyclization is effective for sp(2) as well as aliphatic and benzylic sp(3) C-H bonds.
Scope and Limitations of Auxiliary-Assisted, Palladium-Catalyzed Arylation and Alkylation of sp<sup>2</sup> and sp<sup>3</sup> C–H Bonds
作者:Enrico T. Nadres、Gerson Ivan Franco Santos、Dmitry Shabashov、Olafs Daugulis
DOI:10.1021/jo4013628
日期:2013.10.4
auxiliary-assisted direct arylation and alkylation of sp2 and sp3 C–H bonds of amine and carboxylic acid derivatives has been investigated. The method employs a palladium acetate catalyst, substrate, aryl, alkyl, benzyl, or allyl halide, and inorganic base in tert-amyl alcohol or water solvent at 100–140 °C. Aryl and alkyl iodides as well as benzyl and allyl bromides are competent reagents in this transformation